Trenched is a set of free wargames rules for squad level combat. In spite of the name, it is not a WWI rules set. The example photos are of Warzone science fiction figures.
science fiction
Boonta Eve Classic Podracing Rules
Boonta Eve Classic is a set of free wargmes rules for pod racing in the Star Wars Universe. The rules are designed for use with those old Galoob Micromachines, which can still be had for a reasonable price on Ebay:
Anaxis Space Combat Game
Anaxis is a free space wargame, played on a hex grid with ship counters.
Away Team Astro Miniatures Skirmish Game
Away Team is a set of free wargames rules for a Star Trek-style landing party expeditions.
There’s also a set of 15mm not-Star Trek miniatures.
Firefight Mass Combat
Firefight Mass Combat is a set of free wargames rules originally written for use with Alternative Armies’ 15mm science fiction ranges.